> Oh wait, I expected that "make test" would build Python with PGO, but it
> doesn't anymore. Would it be possible to change the Makefile to make sure
> that "make python" (on Linux, "make python.exe" on macOS) would build Python
> using PGO?
>
> I tried to hack something, but I'm lost in dependencies... "make profile-opt"
> runs "$(MAKE) build_all_generate_profile" which runs "$(MAKE) build_all
> CFLAGS_NODIST=..." and build_all depends on "$(BUILDPYTHON)".
>
> I'm not sure that it's possible to make everything automatic because of the
> high number of targets and dependencies.

In addition, profile-opt would have to rewritten to test whether there's
already an interpreter built with PGO. And if there is, regenerate it only if
the main target is `all` or `profile-opt`, but not when someone runs `make
test`, `make install`, etc.

It's maybe too radical, but we could change it so that if you run `make test`, `make install` and the like and there's no interpreter built already to test or install, the user is told to run `make` first.